ABSTRACT
Candida albicans possui capacidade de causar uma ampla variedade de manifestações clínicas devido a múltiplos fatores de virulência que agem simultaneamente para vencer o sistema imune e invadir os tecidos do hospedeiro. Estudos recentes demonstraram que o crescimento de C. albicans pode ser inibido por metabólitos produzidos por Streptococcus mutans, que estão presentes no sobrenadante da cultura bacteriana. Assim, o objetivo desse estudo foi investigar se o sobrenadante da cultura de S. mutans, além de inibir o crescimento de C. albicans, é capaz de atenuar os mecanismos de virulência desse fungo. Inicialmente, uma suspensão padronizada de S. mutans (107 células/mL) foi incubada em caldo BHI a 37ºC por 4 h em 5% de CO2. O crescimento em BHI foi filtrado em membrana de 0,22 µm, obtendo-se o sobrenadante da cultura de S. mutans livre de células. A seguir, uma suspensão padronizada de C. albicans (107 células/mL) foi adicionada ao sobrenadante filtrado da cultura de S. mutans em caldo BHI, sendo incubada a 37ºC por 24 h. Para os grupos controle, a suspensão de C. albicans foi colocada em caldo BHI ou YPD esterilizados e incubada nas mesmas condições. Após o período de incubação, o crescimento de C. albicans foi centrifugado e lavado para obtenção de uma suspensão padronizada de C. albicans contendo as células sobreviventes da exposição ao sobrenadante de S. mutans. Essa suspensão de C. albicans foi então utilizada nos testes in vitro e in vivo para determinação dos fatores de virulência desse micro-organismo. No estudo in vitro, foi investigada a atividade proteolítica extracelular de C. albicans, bem como sua capacidade de filamentação, adesão e formação de biofilmes (1:30, 6, 24 e 48 h). Para o estudo in vivo, foi utilizado o modelo de Galleria mellonella, analisando-se a curva de sobrevivência, o número de células fúngicas e hemócitos na hemolinfa de larvas infectadas por C. albicans. Para a análise estatística foi utilizado ANOVA, teste de Tukey, Kruskal-Wallis e Log-rank, com nível de significância de 5%. Verificou-se que as células de C. albicans expostas ao sobrenadante de S. mutans apresentaram redução na filamentação, formação de biofilmes e patogenicidade em G. mellonella em relação ao controle. A exposição ao sobrenadante de S. mutans também mudou o padrão de aderência de C. albicans. Entretanto, o sobrenadante de S. mutans não reduziu a atividade proteolítica de C. albicans. Concluiu-se que o sobrenadante de S. mutans apresentou capacidade de inibir importantes mecanismos de virulência de C. albicans, podendo ser uma fonte de novos agentes antifúngicos a ser explorada
Candida albicans has the ability to cause a wide variety of clinical manifestations due to multiple virulence factors that act simultaneously to overcome the immune system and invade host tissues. Recent studies have shown that the growth of C. albicans can be inhibited by metabolites produced by Streptococcus mutans. Thus, the objective of this study was to investigate whether the culture supernatant of S. mutans is able to attenuate the virulence mechanisms of this fungus. Initially, a standardized suspension of S. mutans (107 cells/mL) was incubated in BHI broth at 37ºC for 4 h in 5% CO2. The growth in BHI was filtered through a 0.22 µm membrane, obtaining the cell free culture supernatant of S. mutans. Then, a standardized suspension of C. albicans (107 cells/mL) was prepared and added to the supernatant of the culture of S. mutans in BHI broth, being incubated at 37ºC for 24 h. For the control groups, the suspension of C. albicans was placed in sterile BHI or YPD broth and incubated under the same conditions. After the incubation period, the growth of C. albicans was centrifuged and washed to obtain a standardized suspension of C. albicans containing the surviving cells from exposure to the S. mutans supernatant. This suspension of C. albicans was then used to perform in vitro and in vivo tests to determine the virulence factors of this microorganism. In the in vitro study, the extracellular proteolytic activity of C. albicans was investigated, as well as its capacity for filamentation, adhesion and biofilm formation (1:30, 6, 24 and 48 h). For the in vivo study, the Galleria mellonella model was used, analyzing the survival curve, the number of fungal cells and hemocytes in the hemolymph of larvae infected with C. albicans. For statistical analysis, ANOVA, Tukey's test, Kruskal-Wallis and Log-rank were used, with a significance level of 5%. It was found that the cells of C. albicans exposed to the supernatant of S. mutans showed a reduction in filament, formation of biofilms and pathogenicity in G. mellonella in relation to the control. Exposure to the S. mutans supernatant also changed the pattern of adherence of C. albicans. However, the S. mutans supernatant did not reduce the proteolytic activity of C. albicans. It was concluded that the supernatant of S. mutans had the capacity to inhibit important mechanisms of virulence of C. albicans, being able to be a source of new antifungal agents to be explored.
Subject(s)
Animals , Streptococcus mutans , Candida albicans , Virulence Factors , Virulence , Analysis of Variance , Statistics, Nonparametric , BiofilmsABSTRACT
BACKGROUND Essential oils (EO) extracted from Cinnamomum verum has been used as an antimicrobial agents for centuries. The effects of C. verum leaf oil against virulence of microorganisms is not well studied yet. OBJECTIVES This study evaluates the effect of C. verum leaf oil against three virulence factors of Candida albicans, C. tropicalis and C. dubliniensis and its in-vivo toxicity. METHODS Chemical composition of EO was determined using gas chromatography-mass spectrometry (GC-MS). Minimum inhibitory concentration (MIC) was determined using clinical and laboratory standards institute (CLSI) M27-A3 broth microdilution. Effect of EO on initial adhesion was quantified using XTT assay after allowing Candida cells to adhere to the polystyrene surface for 2 h. Biofilm formation of Candida in the presence of EO was quantified using XTT viability assay. Efficacy on reduction of germ tube formation was evaluated using standard protocol. Visualisation of biofilm formation and progression under the EO treatment were done using scanning electron microscope (SEM) and Time lapses microscope respectively. In-vivo toxicity of EO was determined using Galleria mellonella larvae. Chlorhexidine digluconate: positive control. RESULTS Eugenol was the main compound of EO. MIC was 1.0 mg/mL. 50% reduction in initial adhesion was achieved by C. albicans, C. tropicalis and C. dubliniensis with 1.0, > 2.0 and 0.34 mg/mL respectively. 0.5 and 1.0 mg/mL significantly inhibit the germ tube formation. MBIC50 for forming biofilms were ≤ 0.35 mg/mL. 1.0 mg/mL prevent biofilm progression of Candida. SEM images exhibited cell wall damages, cellular shrinkages and decreased hyphal formation. No lethal effect was noted with in-vivo experiment model at any concentration tested. CONCLUSION C. verum leaf oil acts against virulence factors of Candida and does not show any toxicity.
Subject(s)
Humans , Candida/drug effects , Oils, Volatile , Cinnamomum zeylanicum/chemistry , Virulence Factors , Antifungal AgentsABSTRACT
The objectives of the study were to isolate and identify livestock associated methicillin resistant Staphylococcus aureus (LA-MRSA) and methicillin sensitive S. aureus (LA-MSSA) from clinical mastitis cases and to compare their antibiotic susceptibility, biofilm formation and in vivo pathogenicity in Galleria mellonella larva model. A total of 60 milk samples were collected from cows suffering from mastitis and processed for isolation and identification of S. aureus using standard conventional methods. All the recovered S. aureas isolates were subjected for detection of MRSA and/or MSSA employing phenotypic (Cefoxitin disc assay) and genotypic (the mecA gene PCR) assays. Antibiotic susceptibility pattern of LA-MRSA and LA-MSSA test isolates was determined using disc diffusion method, biofilm formation by 96 well microtiter plate assay and pathogenicity testing in G. mellonella larvae. On microbiological, biochemical and PCR analyses, 14 S. aureus isolates were confirmed. Of these, 4 were tested as LA-MRSA and the remaining 10 isolates were LA-MSSA. Comparative evaluation suggested that MRSA isolates were resistant to different classes of antibiotics and were equally lethal to G. mellonella larvae. However, bioflim forming ability was significantly higher (p < 0.001) in the MSSA test isolates. An association of biofilm formation and pahogenicity testing was not observed between LA-MRSA and LA-MSSA test isolates. Further, LA-MRSA were resistant to different classes of antibiotic and were more lethal to G. mellonella larvae. These preliminary observations are of great concern as the LA-MRSA infections in the community have been documented and warrant in depth research for such pathogens
ABSTRACT
Objective@#To understand the in vitro growth characteristics of Cryptococcus gattii VGⅠ and VGⅡ isolated in China and the diversity in their virulence to Galleria mellonella.@*Methods@#Based on the results of multilocus sequence typing for eight strains of Cryptococcus gattii isolated in China, the strains were cultured in vitro to draw growth curves, observe the melanin production and measure the capsule thickness. The median lethal time (LT50) and median lethal dose (LC50) at 48 h of Cryptococcus gattii were calculated using Galleria mellonella infection test. Fourteen strains of Cryptococcus neoformans were studied for comparison.@*Results@#The eight Cryptococcus gattii strains were six VGⅠ and two VGⅡ. The growth curves of Cryptococcus gattii VGⅠ and VGⅡ were similar to that of Cryptococcus neoformans when culture at 30℃. The total number for each of them could reach 108 CFU/ml at 96 h under 30℃. However, the total number at any time point at 37℃ was less than that at 30℃. There was no significant difference in the amount of melanin produced by Cryptococcus neoformans under 30℃ and 37℃, but both VGⅠand VGⅡ types of Cryptococcus gattii could produce more amount of melanin under 37℃ than under 30℃. The ratio of capsule/cell wall diameter of Cryptococcus gattii VGⅠwas greater at 37℃ than that at 30℃ with statistical significance (P<0.001). Cryptococcus neoformans showed the longest LT50, followed by VGⅠand VGⅡ types of Cryptococcus gattii. The LT50 of Cryptococcus gattii VGⅡ at the concentration of 1×106 CFU/ml was 72 h, and its LC50 at 48 h was 1×108 CFU/ml.@*Conclusions@#Like Cryptococcus neoformans, Cryptococcus gattii VGⅠ and VGⅡ grew faster under 30℃ than under 37℃, but more melanin was produced and thicker capsule was formed under 37℃ than under 30℃. Among Cryptococcus neoformans and VGⅠ and VGⅡ types of Cryptococcus gattii, Cryptococcus gattii VGⅡ showed the shortest LT50 and the strongest virulence to Galleria mellonella.
ABSTRACT
Objective To understand the in vitro growth characteristics of Cryptococcus gattii VGⅠ and VGⅡ isolated in China and the diversity in their virulence to Galleria mellonella. Methods Based on the results of multilocus sequence typing for eight strains of Cryptococcus gattii isolated in China, the strains were cultured in vitro to draw growth curves, observe the melanin production and measure the capsule thickness. The median lethal time (LT50 ) and median lethal dose (LC50 ) at 48 h of Cryptococcus gattii were calculated using Galleria mellonella infection test. Fourteen strains of Cryptococcus neoformans were studied for comparison. Results The eight Cryptococcus gattii strains were six VGⅠ and two VGⅡ. The growth curves of Cryptococcus gattii VGⅠ and VGⅡ were similar to that of Cryptococcus neoformans when culture at 30℃ . The total number for each of them could reach 108 CFU/ ml at 96 h under 30℃ . However, the total number at any time point at 37℃ was less than that at 30℃ . There was no significant difference in the amount of melanin produced by Cryptococcus neoformans under 30℃ and 37℃ , but both VGⅠand VGⅡtypes of Cryptococcus gattii could produce more amount of melanin under 37℃ than under 30℃ . The ratio of capsule/ cell wall diameter of Cryptococcus gattii VGⅠwas greater at 37℃ than that at 30℃ with statistical significance (P<0. 001). Cryptococcus neoformans showed the longest LT50 , followed by VGⅠand VGⅡtypes of Cryptococcus gattii. The LT50 of Cryptococcus gattii VGⅡ at the concentration of 1×106 CFU/ ml was 72 h, and its LC50 at 48 h was 1×108 CFU/ ml. Conclusions Like Cryptococcus neoformans, Cryptococcus gattii VGⅠ and VGⅡ grew faster under 30℃ than under 37℃ , but more melanin was produced and thicker capsule was formed under 37℃ than under 30℃ . Among Cryptococcus neoformans and VGⅠ and VGⅡtypes of Cryptococcus gattii, Cryptococcus gattii VGⅡ showed the shortest LT50 and the strongest virulence to Galleria mellonella.
ABSTRACT
Devido ao aumento das infecções causadas por Candida albicans e espécies não-albicans, surge a necessidade de novas estratégias terapêuticas, como a identificação de cepas bacterianas com características probióticas. Assim, o objetivo foi avaliar a ação antimicrobiana de cepas clínicas de Lactobacillus paracasei, Lactobacillus fermentum e Lactobacillus rhamnosus sobre diferentes espécies de Candida (C. albicans, C. glabrata, C. krusei e C. tropicalis). Foram utilizadas cepas de Lactobacillus isoladas da cavidade bucal de indivíduos livres de cárie e cepas de Candida isoladas de lesões de candidose orofaríngea obtidas em estudos anteriores. Para estudo in vitro, foram formados biofilmes monoespécies de Candida (Grupo controle) e biofilmes mistos de Candida e Lactobacillus, nos quais os lactobacilos foram acrescentados antes da cepa de Candida (Grupo Profilático), após a cepa de Candida (Grupo Terapêutico) ou ao mesmo tempo da cepa de Candida (Grupo Simultâneo). Após 48 h de incubação, foi realizada a contagem do número de células viáveis de Candida (UFC/mL). Para estudo in vivo, os micro-organismos foram inoculados em larvas de G. mellonella e o desenvolvimento da candidose foi monitorado pela curva de sobrevivência, estudando-se os grupos experimentais descritos acima. Nos resultados in vitro, foi verificado que os efeitos inibitórios mais significativos de Lactobacillus sobre Candida ocorreram nos grupos profiláticos. As cepas de C. tropicalis e C. krusei foram mais sensíveis a ação de Lactobacillus do que C. albicans e C. glabrata. Além disso, foi verificado que as três espécies de Lactobacillus estudadas (L. paracasei, L. rhamnosus e L. fermentum) tiveram ação inibitória sobre Candida. Em relação ao estudo in vivo, também foi verificado que os grupos profiláticos tiveram maiores efeitos inibitórios sobre a candidose experimental em relação aos grupos terapêuticos, levando a um aumento significativo nas taxas de sobrevivência das larvas. Em relação as cepas estudadas, os efeitos profiláticos de Lactobacillus sobre a candidose, foram encontrados, de forma semelhante, para todas as cepas de Candida e Lactobacillus estudadas. Assim, concluiu-se que as cepas clínicas de L. paracasei 28.4, L. rhamnosus 5.2 e L. fermentum 20.4 foram capazes de inibir a formação de biofilme e desenvolvimento de candidose causados por C. albicans, C. krusei, C. tropicalis e C. glabrata, principalmente quando Lactobacillus foi administrado de forma profilática(AU)
Due to the increase of infections caused by Candida albicans and non-albicans species, there is a need for new therapeutic strategies, such as the identification of bacterial strains with probiotic characteristics. The objective of this study was to evaluate the antimicrobial action of Lactobacillus paracasei, Lactobacillus fermentum and Lactobacillus rhamnosus strains on different Candida species (C. albicans, C. glabrata, C. krusei and C. tropicalis). We used Lactobacillus strains isolated from the oral cavity of caries-free and Candida strains isolated from lesions of oropharyngeal candidiasis. For in vitro study, monospecies of Candida (Control Group) and mixed biofilms of Candida and Lactobacillus were prepared, in which the lactobacillus were attached before the Candida strain (Profile Group), after a Candida (Therapeutic Group) strain or same time as the Candida strain (Simultaneous Group). After 48 h of incubation, we counting the number of viable Candida cells (CFU/mL). For in vivo study, we inoculate the microorganisms in larvae of G. mellonella and the development of the application for monitoring by survival curve, studying the experimental groups described above. In the in vitro results, we find that the most significant inhibitory effects of Lactobacillus on Candida occurred in the prophylactic groups. The strains of C. tropicalis and C. krusei were more sensitive to the action of Lactobacillus than C. albicans and C. glabrata. In addition, it we verified that the three species of Lactobacillus studied (L. paracasei, L. rhamnosus and L. fermentum) had an inhibitory action on Candida. In relation to the in vivo study, we verified that the prophylactic groups had more inhibitory effects on an experimental candidose in relation to the therapeutic groups, leading to a significant increase in the survival rates of the larvae. In relation to the studied strains, the prophylactic effects of Lactobacillus on candidiasis were similarly for all Candida and Lactobacillus strains studied. Thus, it concluded that the clinical strains of L. paracasei 28.4, L. rhamnosus 5.2 and L. fermentum 20.4 were able to inhibit a biofilm formation and development of Candida caused by C. albicans, C. krusei, C. tropicalis and C. glabrata, especially when Lactobacillus was given prophylactically(AU)
Subject(s)
Humans , Candida/immunology , Dental Plaque/prevention & control , Lactobacillus/pathogenicity , Probiotics/metabolismABSTRACT
Objective@#To establish a Galleria mellonella model of liver abscess-related Klebsiella pneumoniae (K.pneumoniae) infection and to evaluate its feasibility for virulence detection.@*Methods@#Twelve liver abscess-related K. pneumoniae strains were collected in Wuxi No.2 People′s Hospital from January 2016 to December 2017. Twenty K. pneumoniae strains isolated from sputum and urine samples were used as classic strains. All isolates were analyzed by String test. Common capsular serotypes (K1, K2, K5, K16, K20, K54 and K57) of highly virulent K. pneumoniae strains were detected by PCR. Virulence test was performed to measure 80% lethal doses (LD80) of different serotypes in the same time period and the lethal time for 80% of larvae (LT80) at the same concentration.@*Results@#The 12 strains of liver abscess-related K. pneumoniae belonged to five serotypes, which were K1 (41.7%, 5/12), K2 (8.3%, 1/12), K5 (8.3%, 1/12), K20 (8.3%, 1/12) and K57 (33.4%, 4/12). High-virulence serotypes were not detected in the classic group. The positive rates of String test in the liver abscess group and the classic group were 75% and 10% (2/20), respectively. Results of the virulence test showed that when the concentration ranged from 1×105 CFU/ml to 1×108 CFU/ml, the lethal effects of different strains on Galleria mellonella larvae were in a concentration dependent manner. Twelve hours after infection, the numbers of dead larvae in K1 and K57 serotype groups were significantly higher than those in K2, K5, K20 and classic groups. The LD80 values of the liver abscess group at 96 hours after infection were as follows: 1×106 CFU/ml (K1, K57) and 1×107 CFU/ml (K2, K5, K20).@*Conclusion@#The liver abscess-related K. pneumoniae isolates are all highly virulent strains. The virulence of K. pneumoniae can be detected at 12 hours after infection of Galleria mellonella.
ABSTRACT
RESUMEN Los péptidos antimicrobianos (PAMs) juegan un papel importante en la inmunidad innata de la mayoría de los organismos; ellos pueden tener actividad en bacterias, hongos, virus y parásitos. El mecanismo de acción de los PAMs catiónicos yace en la capacidad de interactuar con membranas microbianas, debido a la superficie aniónica de dichas membranas. La familia de las cecropinas fue identificada como una de las familias peptídicas más importantes en los insectos. Los péptidos de esta familia, no contienen residuos de cisteína y son clasificados como helicoidales. Para estudiar el efecto de la carga sobre la estructura, nosotros introducimos residuos cargados positivamente en los primeros 18 aminoácidos de la región N-terminal de la cecropina-D (WT), y se evaluó la actividad biológica de los péptidos modificados. Dos análogos de la cecropina-D con cargas netas de +5 y +9, fueron obtenidos por síntesis de fase sólida (SSP). Los cambios en los péptidos análogos fueron generados de la siguiente manera: péptido +5 con tres sustituciones (E6R, E8R and Q12K) y péptido +9 con cinco sustituciones (E1R, E6R, E8R, Q12K, and D16K). La actividad antibacteriana fue evaluada en dos grupos de bacterias, con el fin de investigar los efectos de las cargas positivas en dicha actividad. Los péptidos catiónicos mostraron una mayor actividad antimicrobiana tanto en bacterias Gram-negativas como en Gram-positivas, a diferencia del péptido WT. Las representaciones en 3D de los péptidos mostraron que ellos tienen una estructura α-hélice. Nuestros resultados demostraron que cambios en la carga de los péptidos incrementa la actividad antibacteriana.
ABSTRACT Antimicrobial peptides (PAMs) play an important role in the innate defense systems of most organisms; they act against bacteria, fungi, viruses and parasites. The mechanism of action of cationic PAMs rely on their capacity to interact with the anionic microbial membrane surface. The cecropin family was identified as one of the most important peptides in insects. Such peptides do not contain cysteine residues and are classified as α-helical. To study the effect of the charge on the peptide structure, we introduced positive charge residues in the last 18 residues at the N-end of cecropin-D (WT) and evaluated the biological activity of the modified peptides. Two analogous peptides from cecropin-D were obtained by synthesis of a solid phase (SSP) with charges of+5 and +9. The analogous peptides were generated as followed: peptide +5 with three substitutions (E6R, E8R and Q12K) and peptide +9 with five substitutions (E1R, E6R, E8R, Q12K, and D16K). Antibacterial activity was evaluated to investigate the effects of the positive charge in these two analogue peptides against two groups of bacteria. The cationic peptides showed higher antimicrobial activity against Gram-negative and Gram-positive bacteria than the WT peptide. The 3D representations of the peptides showed that they have α-helical structure. Our results demonstrate that changes in the charge of peptides increase the antibacterial activity.
ABSTRACT
Muitos produtos probióticos são compostos pela associação de lactobacilos no intuito de potencializar seu efeito benéfico. Assim, o objetivo deste estudo foi avaliar a imunomodulação e atividade anti-Candida causada por diferentes combinações de suspensões probióticas em macrófagos e em Galleria mellonella. Lactobacillus rhamnosus (LR), L. acidophilus (LA), e L. paracasei (LP) foram suspendidos para obtenção das suspensões LR, LA, LP, LR+LA, LR+LP, LA+LP e LR+LA+LP. Foram utilizadas suspensões de Candida albicans (CA) ATCC 18804, C. krusei (CK) ATCC 6258 e C. glabrata (CG) ATCC 9030. Macrófagos de camundongo (RAW 264.7) foram ativados por cada suspensão de lactobacilos e desafiados por cada uma das cepas fúngicas. Foram investigadas taxa de fagocitose, produção de citocinas e óxido nítrico e a viabilidade celular. A melhor suspensão probiótica para cada cepa fúngica seria usada nos testes in vivo, com G. mellonella, no entanto, devido à baixa virulência das espécies não-albicans, os testes in vivo prosseguiram com CA e LR. Duas cepas clínicas de CA foram acrescentadas: 21 e 60. Suspensões de LR foram injetadas na hemolinfa das larvas 24 h antes do desafio com as cepas fúngicas. Foram determinadas curva de sobrevivência, contagem de UFC/mL das cepas de C. albicans e de hemócitos. Os resultados foram analisados estatisticamente de acordo com a distribuição normal (ANOVA e Tukey ou Kruskal-Wallis e Dunn) e a curva de sobrevivência pelo teste de Log-rank (Mantel-Cox), p<0,05. As melhores suspensões para CA, CK e CG foram LR (com melhores resultados no perfil de citocinas), LP e LA (com melhores resultados sobre a fagocitose), respectivamente. Em G. mellonella, a suspensão de LR proporcionou aumento da percentagem de sobrevivência e do número de hemócitos e diminuição da contagem de UFC/mL em todos os grupos com diferenças estatisticamente significantes. Sendo assim, pode-se concluir que as suspensões de lactobacilos possuem potencial imunomodulador cepa dependente mas sua mistura não favorece essa qualidade. Além disso, possuem atividade anti-Candida, demonstrada pela diminuição na contagem de Candida(AU)
Many probiotic products are composed by association of lactobacilli in order to potentiate their beneficial effect. Therefore, the objective of this study was evaluating the immunomodulation and anti-Candida activity caused by different combinations of probiotic suspensions in macrophages and in Galleria mellonella. Lactobacillus rhamnosus (LR), L. acidophilus (LA) and L. paracasei (LP) were suspended to obtain the suspensions LR, LA, LP, LR + LA, LR + LP, LA + LP and LR + LA + LP. Suspensions of Candida albicans (CA) ATCC 18804, C. krusei (CK) ATCC 6258 and C. glabrata (CG) ATCC 9030 were used. Mouse macrophages (RAW 264.7) were activated by each suspension of lactobacilli and then challenged by each fungal strain. Phagocytosis, cytokine and nitric oxide production and cell viability were investigated. The best lacobacilli suspension for each fungal strain would be used in the in vivo assays with G. mellonella, however, because of low virulence of the non-albicans species, in vivo tests were performed with CA and LR. Two clinical strains of CA were added: 21 and 60. LR suspensions were injected into the haemolymph of the larvae 24 h before challenging with fungal strains. Survival curve, CA strains CFU/mL counting and hemocytes were determined. The results were statistically analyzed according to their normal distribution (ANOVA and Tukey or Kruskal-Wallis and Dunn) and the survival curve by Log-rank test (MantelCox), p <0.05. The best suspensions for CA, CK and CG were LR (which obtained the best results in the cytokine profile), LP and LA (which obtained the best results on phagocytosis), respectively. In G. mellonella, LR suspension increased percentage survival and hemocyte counting and decreased CFU/mL counting in all groups, with statistically significant differences in the results. Thus, it can be concluded that the suspensions of lactobacilli have immunomodulatory potential strain-dependent but their association does not favor this quality. Besides, they showed anti-Candida activity, demonstrated by the decrease of Candida counting (AU)
Subject(s)
Humans , Candida , Immunomodulation , MacrophagesABSTRACT
Galleria mellonella é utilizada para estudar a virulência de microorganismose a potência de antimicrobianos. Este estudo buscou estabelecer criação de lagartas utilizadas em ensaios in vivo e avaliar o efeito do probiótico Lactobacillus rhamnosus ATCC 7469, inativado pelo calor, no modelo e in vitro. Os objetivos foram: a) desenvolver uma metodologia de criação de G. mellonella, avaliando quatro dietas diferentes sobre crescimento larval, volume da hemolinfa, quantidade de hemócitos e resposta à infecção por meio da curva de sobrevivência b) avaliar os efeitos de L. rhamnosus sobre G. mellonella analisando: curva de sobrevivência; contagem de hemócitos, melanização da hemolinfa, produção de óxido nítrico na hemolinfa e os efeitos de L. rhamnosussobre macrófagos RAW 264.7 desafiados por S. aureus ou E. coli, analisando o perfil de indução de citocinas e óxido nítrico. Os resultados foram analisados estatisticamente (ANOVA e Tukey, 5%) e a curva de morte e estimativa das diferenças na sobrevivência foram determinadas por Log-rank (Mantel-Cox, 5%). As rações a base de fubá e pólen apresentaram os melhores resultados, sendo semelhantes entre si e diferentes das demais rações (p < 0,05), sendo a ração a base de fubá escolhida por apresentar resultados semelhante ao pólen e menor custo. Os resultados in vivo demonstraram diminuição na mortalidade das lagartas no grupo com inoculação de L. rhamnosus, entretanto, sem diferença estatística. Houve aumento na contagem de hemócitos quando G. mellonella foi inoculada com S. aureus e E. coli, com ou sem inoculação de L. rhamnosus, além de haver melanização da hemolinfa,demonstraram que o L. rhamnosus melhorou a resposta de G. mellonella quando desafiada por bactérias. Os resultados in vitro demonstram que L.rhamnosus induziu alta produção de TNF-α, igualmente aos demais grupos (p ≤ 0,05), não havendo produção de IL-1β e IL-6 no grupo estimulado apenas por L. rhamnosus. Nos grupos que receberam o segundo estímulo ou ...
Galleria mellonella is used to study microorganisms virulence and antimicrobial power. This study aimed to standardize the creation of worms used in In vivo assays and evaluate the effect of heat-killed probiotic, Lactobacillus rhamnosus ATCC 7469, on this model and in in vitro studies. The objectives were: a) developing a methodology for breeding G. mellonella with four different diets influence on larval growth,hemolymph volume, quantity of hemocytes and infection response bymeans of survival curve; b) evaluating the effects of L. rhamnosus on G.mellonella by means of the following analyzes: survival curve, hemocytes counting, hemolymph melanization, nitric oxide release, and the effects ofL. rhamnosus on macrophages RAW 264.7 challenged by S. aureus or E.coli by means of cytokines and nitric oxide production. Results were statistically analyzed (ANOVA and Tukey, 5%). Death curve and estimation of differences in survival were determined by Log-rank (MantelCox, and pollen-based rations showed the best results, being similar to each other and different from the other ones (p <0.05).Cornmeal ration was chosen since it presents results similar topollen and lower cost. In vivo results showed reduction in mortality of caterpillars in the group inoculated with L. rhamnosus, with no statistical difference. Hemocyte counting increased when G. mellonella was inoculated with S. aureus and E. coli, with or with out inoculation of L. rhamnosus, add to that hemolymph melanization, showing that L.rhamnosus improved G. mellonella response challenged by bacteria. Invitro results show that L. rhamnosus induced high production of TNF-α,like other groups (p = 0.05), with no production of IL-1β and IL-6 in thegroup stimulated only by L. rhamnosus. The groups which received only the second stimulus or only the contact with S. aureus or E. coli, there wasIL-1β, IL-6 and IL-10 production. The highest nitric oxide production was observed in the groups challenged...
Subject(s)
Cytokines , Lacticaseibacillus rhamnosus , Macrophages , Nitric OxideABSTRACT
Galleria mellonella é utilizada para estudar a virulência de microorganismose a potência de antimicrobianos. Este estudo buscou estabelecer criação de lagartas utilizadas em ensaios in vivo e avaliar o efeito do probiótico Lactobacillus rhamnosus ATCC 7469, inativado pelo calor, no modelo e in vitro. Os objetivos foram: a) desenvolver uma metodologia de criação de G. mellonella, avaliando quatro dietas diferentes sobre crescimento larval, volume da hemolinfa, quantidade de hemócitos e resposta à infecção por meio da curva de sobrevivência b) avaliar os efeitos de L. rhamnosus sobre G. mellonella analisando: curva de sobrevivência; contagem de hemócitos, melanização da hemolinfa, produção de óxido nítrico na hemolinfa e os efeitos de L. rhamnosussobre macrófagos RAW 264.7 desafiados por S. aureus ou E. coli, analisando o perfil de indução de citocinas e óxido nítrico. Os resultados foram analisados estatisticamente (ANOVA e Tukey, 5%) e a curva de morte e estimativa das diferenças na sobrevivência foram determinadas por Log-rank (Mantel-Cox, 5%). As rações a base de fubá e pólen apresentaram os melhores resultados, sendo semelhantes entre si e diferentes das demais rações (p < 0,05), sendo a ração a base de fubá escolhida por apresentar resultados semelhante ao pólen e menor custo. Os resultados in vivo demonstraram diminuição na mortalidade das lagartas no grupo com inoculação de L. rhamnosus, entretanto, sem diferença estatística. Houve aumento na contagem de hemócitos quando G. mellonella foi inoculada com S. aureus e E. coli, com ou sem inoculação de L. rhamnosus, além de haver melanização da hemolinfa,demonstraram que o L. rhamnosus melhorou a resposta de G. mellonella quando desafiada por bactérias. Os resultados in vitro demonstram que L.rhamnosus induziu alta produção de TNF-α, igualmente aos demais grupos (p ≤ 0,05), não havendo produção de IL-1β e IL-6 no grupo estimulado apenas por L. rhamnosus. Nos grupos que receberam o segundo estímulo...
Galleria mellonella is used to study microorganisms virulence and antimicrobial power. This study aimed to standardize the creation of worms used in In vivo assays and evaluate the effect of heat-killed probiotic, Lactobacillus rhamnosus ATCC 7469, on this model and in in vitro studies. The objectives were: a) developing a methodology for breeding G. mellonella with four different diets influence on larval growth,hemolymph volume, quantity of hemocytes and infection response bymeans of survival curve; b) evaluating the effects of L. rhamnosus on G.mellonella by means of the following analyzes: survival curve, hemocytes counting, hemolymph melanization, nitric oxide release, and the effects ofL. rhamnosus on macrophages RAW 264.7 challenged by S. aureus or E.coli by means of cytokines and nitric oxide production. Results were statistically analyzed (ANOVA and Tukey, 5%). Death curve and estimation of differences in survival were determined by Log-rank (MantelCox, and pollen-based rations showed the best results, being similar to each other and different from the other ones (p <0.05).Cornmeal ration was chosen since it presents results similar topollen and lower cost. In vivo results showed reduction in mortality of caterpillars in the group inoculated with L. rhamnosus, with no statistical difference. Hemocyte counting increased when G. mellonella was inoculated with S. aureus and E. coli, with or with out inoculation of L. rhamnosus, add to that hemolymph melanization, showing that L.rhamnosus improved G. mellonella response challenged by bacteria. Invitro results show that L. rhamnosus induced high production of TNF-α,like other groups (p = 0.05), with no production of IL-1β and IL-6 in thegroup stimulated only by L. rhamnosus. The groups which received only the second stimulus or only the contact with S. aureus or E. coli, there wasIL-1β, IL-6 and IL-10 production. The highest nitric oxide production was observed in the groups challenged...
Subject(s)
Cytokines , Lacticaseibacillus rhamnosus , Macrophages , Nitric OxideABSTRACT
Dried, fresh and glycolic extracts of Zingiber officinale were obtained to evaluate the action against G. mellonella survival assay against Enterococcus faecalis infection. Eighty larvae were divided into: 1) E. faecalis suspension (control); 2) E. faecalis + fresh extract of Z. officinale (FEO); 3) E. faecalis + dried extract of Z. officinale (DEO); 4) E. faecalis + glycolic extract of Z. officinale (GEO); 5) Phosphate buffered saline (PBS). For control group, a 5 μL inoculum of standardized suspension (107 cells/mL) of E. faecalis (ATCC 29212) was injected into the last left proleg of each larva. For the treatment groups, after E. faecalis inoculation, the extracts were also injected, but into the last right proleg. The larvae were stored at 37 °C and the number of dead larvae was recorded daily for 168 h (7 days) to analyze the survival curve. The larvae were considered dead when they did not show any movement after touching. E. faecalis infection led to the death of 85% of the larvae after 168 h. Notwithstanding, in treatment groups with association of extracts, there was an increase in the survival rates of 50% (GEO), 61% (FEO) and 66% (DEO) of the larvae. In all treatment groups, the larvae exhibited a survival increase with statistically significant difference in relation to control group (p=0.0029). There were no statistically significant differences among treatment groups with different extracts (p=0.3859). It may be concluded that the tested extracts showed antimicrobial activity against E. faecalis infection by increasing the survival of Galleria mellonella larvae.
Extratos seco, fresco e glicólico de Zingiber officinale foram obtidos para avaliar suas ações por meio de ensaio de sobrevivência em G. mellonella contra infecção por Enterococcus faecalis. Oitenta larvas foram divididas em: 1) Suspensão de E. faecalis (controle); 2) E. faecalis + extrato fresco de Z. officinale (FEO); 3) E. faecalis + extrato seco de Z. officinale (DEO); 4) E. faecalis + extrato glicólico de Z. officinale (GEO); 5) Solução tampão fosfato salina (PBS). Para o grupo de controle, 5 µL de inóculo de suspensão padronizada (107 células/mL) de E. faecalis (ATCC 29212) foi injetado na última proleg esquerda de cada lagarta. Para os grupos com tratamento, após a injeção de E. faecalis, os extratos foram injetados na última proleg direita. Após as injeções, as lagartas foram armazenadas a 37 °C e o número de animais mortos foi registrado diariamente em 168 h (7 dias) para analisar a curva de sobrevivência. As lagartas foram consideradas mortas quando elas não mostraram qualquer movimento após o toque. A infecção por E. faecalis levou à morte de 85% das lagartas após 168 h. Não obstante, nos grupos de tratamento com associação dos extratos, houve um aumento nas taxas de sobrevivência de 50% (GEO), 61% (FEO) e 66% (DEO) das lagartas. Em todos os grupos com tratamento, as lagartas apresentaram um aumento na sobrevivência, com diferença estatisticamente significativa em relação ao grupo controle (p=0,0029). Não houve diferença estatisticamente significativa entre os tratamentos com os diferentes extratos (p=0,3859). Pode concluir-se que os extratos testados mostraram atividade antimicrobiana contra a infecção por E. faecalis, aumentando a sobrevivência das lagartas de G. mellonella.
Subject(s)
Humans , Receptors, GABA-A/chemistry , Binding Sites , Benzamidines/chemistry , Benzamidines/metabolism , Benzamidines/pharmacology , Conserved Sequence , Crystallography, X-Ray , Cell Membrane/chemistry , Cell Membrane/metabolism , Drug Design , GABA-A Receptor Agonists/chemistry , GABA-A Receptor Agonists/metabolism , GABA-A Receptor Agonists/pharmacology , Genetic Predisposition to Disease , Glycosylation , Models, Molecular , Mutation/genetics , Protein Structure, Quaternary , Protein Structure, Tertiary , Protein Subunits , Polysaccharides/chemistry , Polysaccharides/metabolism , Receptors, GABA-A/genetics , Synaptic TransmissionABSTRACT
Devido ao rápido aumento dos micro-organismos resistentes aos antibióticos e ao desenvolvimento limitado de novos agentes antimicrobianos, as infecções por bactérias Gram-negativas estão se tornando um desafio para os profissionais da saúde e uma ameaça para a saúde pública internacional. O objetivo desse estudo foi avaliar o efeitos inérgico dos antibióticos convencionais associados a terapia fotodinâmica antimicrobiana (PDT) no controle de Acinetobacter baumannii. Para realização desse trabalho, foram obtidos isolados clínicos de A. baumannii do Laboratório de Análises Clínicas Valeclin da cidade de São José dos Campos/SP, identificados pelo método de bioquimismo e submetidos ao teste de difusão em disco para verificar a sensibilidade antimicrobiana. Os isolados selecionados foram transferidos para o ICT/UNESP, onde foi realizado testes para determinação da Concentração Inibitória Mínima aos antibióticos Imipenem e Meropenem seguindo as normas da CLSI. Cepas sensíveis e resistentes aos antibióticos foram avaliadas quanto a sensibilidade in vitro à terapia fotodinâmica antimicrobiana. Além disso, foram testados os efeitos dos antibióticos convencionais, da PDT e da terapia combinada de antibióticose PDT nas infecções experimentais induzidas em G. mellonella por isolados clínicos de A. baumannii resistentes aos antibióticos. Os resultados das terapias na infecção experimental foram avaliados por meio da curva de sobrevivência das lagartas de G. mellonella. Os dados dos testes in vitro foram submetidos à Análise de Variância e teste deTukey. Os dados obtidos na curva de sobrevivência de G. mellonella foram analisados pelo método de Log-rank. Em todos os testes, foi considerado nível de significância de 5%. Nos resultados desse estudo,observou-se que o Laboratório Valeclin identificou 1,54% de amostras positivas para A. baumannii entre as 13.715 amostras clínicas analisadas em um período de 8 meses. Entre os isolados de A. baumannii, ...
Due to the rapid growth of microorganisms resistant to antibiotics and the limited development of new antimicrobial agents, infections by Gramnegative bacteria are becoming a challenge for health professionals and athreat to international public health. The aim of this study was to evaluatethe synergistic effect of conventional antibiotics associated with antimicrobial photodynamic therapy (PDT) in control of Acinetobacter baumannii. In order to conduct this project were obtained clinical isolatesof A. baumannii at the Clinical Laboratory Valeclin situated in the city ofSão José dos Campos / SP, identified by bioquimismo method and submitted to disk diffusion test to verify the antimicrobial sensitivity. The selected isolates were transferred to the ICT / UNESP, which were conducted tests to determine the Minimum Inhibitory Concentration to Imipenem and Meropenem antibiotics following the rules of the CLSI.Sensitive and resistant strains to antibiotics were evaluated in vitro sensitivity to antimicrobial photodynamic therapy. Besides, the effects of conventional antibiotics, and combined PDT, and PDT of antibiotics in experimental infections induced in G. mellonella by clinical isolates of A.baumannii resistant to antibiotic therapy were tested. The results of therapies in experimental infection were evaluated by survival curve of worms G. mellonella. Data from in vitro tests were submitted to ANOVA and Tukey test. The data obtained in G. mellonella survival curve were analyzed by log-rank method. In all tests it was considered 5% significance level. The results of this study, it was observed that the Valeclin Laboratory identified 1.54% of positive samples for A. baumannii between the 13,715 clinical specimens analyzed in a period of 8 months.Among the isolates of A. baumannii, 58% were resistant to antibiotic imipenem and meropenem by disk diffusion test. Next, 3 isolates clinical sensitive and 18 isolates ...
Subject(s)
Acinetobacter baumannii , Anti-Infective Agents , Drug Resistance, MicrobialABSTRACT
Devido ao rápido aumento dos micro-organismos resistentes aos antibióticos e ao desenvolvimento limitado de novos agentes antimicrobianos, as infecções por bactérias Gram-negativas estão se tornando um desafio para os profissionais da saúde e uma ameaça para a saúde pública internacional. O objetivo desse estudo foi avaliar o efeitos inérgico dos antibióticos convencionais associados a terapia fotodinâmica antimicrobiana (PDT) no controle de Acinetobacter baumannii. Para realização desse trabalho, foram obtidos isolados clínicos de A. baumannii do Laboratório de Análises Clínicas Valeclin da cidade de São José dos Campos/SP, identificados pelo método de bioquimismo e submetidos ao teste de difusão em disco para verificar a sensibilidade antimicrobiana. Os isolados selecionados foram transferidos para o ICT/UNESP, onde foi realizado testes para determinação da Concentração Inibitória Mínima aos antibióticos Imipenem e Meropenem seguindo as normas da CLSI. Cepas sensíveis e resistentes aos antibióticos foram avaliadas quanto a sensibilidade in vitro à terapia fotodinâmica antimicrobiana. Além disso, foram testados os efeitos dos antibióticos convencionais, da PDT e da terapia combinada de antibióticose PDT nas infecções experimentais induzidas em G. mellonella por isolados clínicos de A. baumannii resistentes aos antibióticos. Os resultados das terapias na infecção experimental foram avaliados por meio da curva de sobrevivência das lagartas de G. mellonella. Os dados dos testes in vitro foram submetidos à Análise de Variância e teste deTukey. Os dados obtidos na curva de sobrevivência de G. mellonella foram analisados pelo método de Log-rank. Em todos os testes, foi considerado nível de significância de 5%. Nos resultados desse estudo,observou-se que o Laboratório Valeclin identificou 1,54% de amostras positivas para A. baumannii entre as 13.715 amostras clínicas analisadas em um período de 8 meses. Entre os isolados de A...
Due to the rapid growth of microorganisms resistant to antibiotics and the limited development of new antimicrobial agents, infections by Gramnegative bacteria are becoming a challenge for health professionals and athreat to international public health. The aim of this study was to evaluatethe synergistic effect of conventional antibiotics associated with antimicrobial photodynamic therapy (PDT) in control of Acinetobacter baumannii. In order to conduct this project were obtained clinical isolatesof A. baumannii at the Clinical Laboratory Valeclin situated in the city ofSão José dos Campos / SP, identified by bioquimismo method and submitted to disk diffusion test to verify the antimicrobial sensitivity. The selected isolates were transferred to the ICT / UNESP, which were conducted tests to determine the Minimum Inhibitory Concentration to Imipenem and Meropenem antibiotics following the rules of the CLSI.Sensitive and resistant strains to antibiotics were evaluated in vitro sensitivity to antimicrobial photodynamic therapy. Besides, the effects of conventional antibiotics, and combined PDT, and PDT of antibiotics in experimental infections induced in G. mellonella by clinical isolates of A.baumannii resistant to antibiotic therapy were tested. The results of therapies in experimental infection were evaluated by survival curve of worms G. mellonella. Data from in vitro tests were submitted to ANOVA and Tukey test. The data obtained in G. mellonella survival curve were analyzed by log-rank method. In all tests it was considered 5% significance level. The results of this study, it was observed that the Valeclin Laboratory identified 1.54% of positive samples for A. baumannii between the 13,715 clinical specimens analyzed in a period of 8 months.Among the isolates of A. baumannii, 58% were resistant to antibiotic imipenem and meropenem by disk diffusion test. Next, 3 isolates clinical sensitive and 18 isolates...
Subject(s)
Acinetobacter baumannii , Anti-Infective Agents , Drug Resistance, MicrobialABSTRACT
Esporotricose é uma micose subcutânea causada pelo fungo dimórfico previamente descrito como uma única espécie, Sporothrix schenckii, agora entendido como um complexo de diferentes espécies de interesse clínico. A região metropolitana do Rio de Janeiro constitui área hiperendêmica de esporotricose zoonótica transmitida por gatos desde 1998. Clinicamente tem se caracterizado por formas clínicas pouco usuais, manifestações de hipersensibilidade e um número crescente de pacientes coinfectados com HIV. Este estudo teve como objetivo avaliar fatores epidemiológicos, micológicos, clínicos e terapêuticos associados às diversas formas clínicas de pacientes com esporotricose. Foram utilizados o banco hospitalar de registros de pacientes e o banco de cepas do laboratório de micologia do Instituto de Pesquisa Clínica Evandro Chagas (IPEC), bem como técnicas de identificação genotípica e laboratoriais clássicas para determinação de virulência e fenótipo dos isolados fúngicos. Foi verificado que a dacriocistite aguda (quatro casos entre 2008 e 2010) é uma manifestação da esporotricose que evolui com complicações (fístula e dacriocistite crônica) necessitando reparação cirúrgica. A Síndrome de Sweet foi observada em três pacientes até 2010 e deve ser incorporada como manifestação de hipersensibilidade da esporotricose...
Sporotrichosis is a subcutaneous mycosis caused by the dimorphic fungus previously described as a single species, Sporothrix schenckii, now understood as a complex of different species of clinical interest. The metropolitan region of Rio de Janeiro is an endemic area of zoonotic sporotrichosis transmitted by cats since 1998. Clinically, it has been characterized by unusual clinical presentations, manifestations of hypersensitivity and an increasing number of patients coinfected with HIV. This study aimed to evaluate epidemiological, mycological, clinical and therapeutic factors associated with different clinical aspects of patients with sporotrichosis. The hospital database of patient records and the stock strains of the laboratory of mycology of Instituto de Pesquisa Clínica Evandro Chagas (IPEC) were used, as well as techniques for genotypic identification and classical laboratory tools for determination of virulence and phenotype of the fungal isolates. It was found that acute dacryocystitis (4 cases between 2008 and 2010) is a manifestation of sporotrichosis which evolves with complications (fistula and chronic dacryocystitis) requiring surgical repair. Sweet syndrome was observed in three patients until 2010 and should be incorporated as a manifestation of hypersensitivity of sporotrichosis...
Subject(s)
Humans , Pregnancy , Cats , AIDS-Related Opportunistic Infections , Sporotrichosis/diagnosis , Sporotrichosis/epidemiology , HIV , Sweet SyndromeABSTRACT
In the present study, the interactions of entomopathogenic fungi viz., Beauveria bassiana, Beauveria brongniartii and Metarhizium anisopliae among themselves and three other opportunistic soil fungi from the sugarcane ecosystem namely, Fusarium saachari, Aspergillus sp. and Penecillium sp. were assayed in vivo against Galleria mellonella larvae. The tested fungi were co-applied on IV instar G. mellonella @ 1x 107 ml-1, in combinations of two, at the interval of 24 hrs either preceding or succeeding each other to assess their efficacy and sporulation rates. Results showed that often mortality rates did not correspond to the spore harvest of the mortality agent and presence of other fungus may be antagonistic. The efficacy of B. bassiana (90%) and B. brongniartii (100%) was not enhanced further but was negatively affected in most combinations with other fungi. In case of M. anisopliae compatibility was higher, resulting in higher mortality by application of B. bassiana before (100%) or after (83.3%) M. anisopliae than when it was applied alone (70%). During sporulation, B. bassiana faced the most intense competition from M. anisopliae (2.75x106 larva-1) and enhancement due to F. sacchari irrespective of sequence of application. In case of B. brongniartii, sporulation was lowest in the combination of B. brongniartii preceding M. anisopliae (1.83 x106 larva-1) and B. brongniartii succeeding B. bassiana (1.58x106 larva-1). Of all fungi tested, except F. sacchari (65.33 x 106 larva-1) all the other species affected sporulation of M. ansiopliae with the least in treatment of B. bassiana application following M. anisopliae. Similar kind of interaction was observed during sporulation of soil fungi when combined with entomopathogenic fungi, though individually they could not cause mortality of larvae.